1. Field of the Invention
The present invention relates to radial plunger pumps, and particularly, to a radial plunger pump having a plurality of plungers arranged at substantially regular intervals around an outer periphery of a driving shaft, and to a method for manufacturing a pump housing.
2. Description of the Related Art
Japanese Patent Application Laid-Open No. 2001-500593 discloses an example of a radial plunger pump of the above-mentioned type, in which a pump housing is provided for supporting a driving shaft in a rotatable manner. The pump housing has a plurality of cylinder bores extending radially and arranged at substantially regular intervals around the outer periphery of the driving shaft. Each cylinder bore has a plunger fitted therein, which reciprocates in response to the rotation of the driving shaft.
In the above-described plunger pump, an inlet, an inlet valve, an outlet, and an outlet valve are provided for each plunger. Fluid flowing from an inlet port provided in the pump housing passes through an inlet passage and flows into each inlet. Moreover, fluid flowing from each outlet passes through an outlet passage and flows into an outlet port provided in the pump housing.
According to such a conventional radial plunger pump described above, the outlet passage has a plurality of communication holes corresponding to the outlet valves. Outlet ends of the communication holes are connected to different sections of the outlet port. For this reason, the conventional radial plunger pump has a plurality of connecting sections between the communication holes and the outlet port. In other words, the radial plunger pump has a plurality of sections where burrs are formed. This means that a burr-removal process is necessary for each of the connecting sections between the communication holes and the outlet port, which is problematic in view of work efficiency and reliability.